Conventional male/female couplings have long been used to sealingly join pressurized fluid lines. The coupling halves, when joined, automatically enable the fluid and/or fluid pressure to be transmitted through the coupling without a significant pressure differential. When unmated, the valve poppet in the body of each coupler half automatically seals the fluid within each coupler body and its respective fluid line. Such couplers are able to reliably maintain high fluid pressure after repeated mating and unmating operations.
The seal between the joined coupling halves may conventionally be provided by either an elastomeric or metallic member. For many applications, the low cost, chemically inert quality, and non-corrosive characteristics of elastomeric materials has resulted in the commonplace use of such sealing members, including elastomeric seals manufactured from natural or synthetic rubber, Teflon, nylon, PEEK, or similar materials. In other applications, especially those wherein high reliability is paramount, metallic seals are preferable.
One type of coupler suitable for reliably interconnecting fluid lines employs a metallic face seal. Sealing engagement is provided by a metallic seal sandwiched between surfaces of the coupler halves, with each sealing surface being generally perpendicular to the axis of the coupler. One disadvantage of such couplers involves the significant axially-directed force necessary to mate the coupler halves, since the mating operation is resisted by both friction and the axially-directed biasing force of the compressible sealing member. Another significant disadvantage of metallic face seals relates to the difficulty in maintaining proper axial tolerances between these sealing surfaces.
Other types of couplers employ metallic radial seals which are sealingly responsive to fluid pressure. Current designs for these types of couplers are, however, susceptible to poor reliability. The male cylindrical surface to be engaged by the radial seal may contain debris which adversely affects sealing integrity. Sealing reliability of an elastomeric secondary radial seal is poor, and retainers for the seals are susceptible to blowout under high pressure pulsations.
The disadvantages of the prior art are overcome by the present invention, and an improved highly reliable coupler is hereinafter described.